A great variety of gate arrays are known in the prior art. Configurable gate arrays, including particularly laser configurable gate arrays, are also known and are used in prototype and short run applications. The following U.S. Patents of the present applicant/assignee relate to configurable gate arrays: U.S. Pat. Nos. 4,875,971; 4,924,287; 4,933,738; 4,960,729; 5,049,969; 5,111,273; 5,138,194; 5,260,597; 5,329,152.
Generally in the prior art, in order to be conveniently laser configurable, the configuration of the logic cells and their contacts in configurable gate arrays is such that the overall density is relatively low, thus rendering such gate arrays uneconomical for mass applications.